用所给单词的适当形式完成句子。

1. Is it right                _______ (experiment) on animals?

2. What's the ________ (mean) of this? Why have you left your clothes untidily on the floor?.

3. We hired two rooms with _______ (connect) doors.

4. We are collecting _______ (donate) for the homeless children.

5. Our teacher __________ (communicate) his ideas very clearly.